Biological Imperatives
by LionessInTheSmoke
Summary: Omegaverse AU Johnlock with Omega!Sherlock and Alpha!John. If that's all Greek to you, don't read this until you've done some research and know it won't squick you. Even then, read the AN for further warnings. There are two parts (John-Era, Pre-John-Era) and an epilogue (Post-Fall), basically, John gets an omega, Mycroft "arranges" an alpha for Sherlock and finally John is angry...


**AN : This is (one version of) the Omegaverse and therefore AU. If you don't know what that is, find out _before_ you read this. There is questionable consent, dominance and mention of drug use. If these are triggers for you, do not read this. It is rated M for all these reasons, and for the crude language and (unrealistic) sex.  
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**Additionally, this is Johnlock but includes mentions of Sherlock's other partners (Holmescest and Victorbashing). If this squicks you out, stop now.**

**I do not own any of this except the story and make no money from it. I apologize whole-heartedly for what I have done to all those who do in some way "own" these characters.  
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* * *

**Everything Is Perfectly Clear**

The Middle

"Oh marvellous!" Sherlock Holmes grinned and rubbed his hands together. "Everybody out! Now! I need space for my thoughts."

There was some shuffling of feet and some questioning looks were thrown at DI Lestrade, but most of the team were used to the behaviour of the World's only Consulting Detective and left as instructed, even as Lestrade gave a tired nod and made a shooing gesture with his hands to the stragglers.

"Five minutes please everyone."

Sherlock knelt by the body and began his scanning for information. Doctor John Watson stood quietly at the side of the room and observed, waiting until he was called to take his turn. He knew it won't be long.

Sherlock was clearly delighted with whatever he was seeing. He beamed and, with a loud sigh of "Clever!", he beckoned the doctor over.

"Do you see that John?!"

As the doctor knelt down beside him, Sherlock fished his magnifying glass out of his pocket and held it over a puncture mark for John. John wrinkled his nose slightly.

"I see it Sherlock."

"It's brilliant!" Enthused the detective and jumped to his feet to pace, his coat billowing behind him.

John gave a deep sniff. He was utterly sure now. How unfortunate.

"Ponderous House, Sherlock" He said calmly and pushed himself up to his feet.

"What?" Asked the detective coming to an abrupt holt. "Now?" He seemed to turn his thoughts inward for a second, before announcing in a quiet voice; "Oh."

"Yes Sherlock, now."

"But why now?" The detective's voice was decidedly whinny to John's ear.

"I am going to call a cab, tell Greg what you know. Thirty minutes Sherlock, so keep it short." John's voice was firm, ignoring Sherlock's pout.

John stepped from the room, checked he had the hall to himself and called a number he had stored on his phone for just such situations.

"Hello, Beta Cab Services?" A woman's voice answered the call.

"I need a cab immediately for the following address. Tell the driver to switch the filters on. I will meet her at the gate."

"Yes sir. You know we will have to charge emergency rates for fumigating the car?"

"Yes, yes it's fine. It's on the Holmes account." John gave the address and waited impatiently.

"We have someone just one minute away. I will get her diverted straight to you."

"Thank you" said John letting out a relieved breath, he ended the call and went to collect Sherlock.

"... which is how I know you are looking for a man of about 5"8', who has recently arrived from Uganda and almost certainly has links to the travel industry." Sherlock finished his explanation to the detective inspector with decidedly bad grace.

"Thank you Sherlock" said Lestrade, clearly trying to get his head around all the information he had just had dumped on him. "That was very helpful."

Sherlock gave a pained sounding "Hhrumpf".

"Time to go Sherlock." John broke in before anything else could be said. They were cutting it fine as it was to get back to Baker Street from here. Sherlock gave another "Hhrumpf" and swept from the room, John directly on his heels.

Lestrade stroked his chin. He had seen this happen a couple of times now. John would say something that was clearly a code word and the pair would suddenly depart. It was always on cases that Lestrade would have expected Sherlock to be really interested in too, the really odd ones, but he always listened to John once that code was given. Even if he did seem to sulk like a sixteen year old in the process.

John kept directly on Sherlock's heels, despite the longer legs of the detective, as they left the house and he was pleased to see the cab was waiting for them at the gate. He was absolutely delighted that they hadn't met either Donovan or Anderson on the way out, the alphas could not fail to notice the signs of Sherlock's arousal (as they had on numerous occasions, although they attributed it to the wrong cause).

Sherlock threw himself into the car and folded his arms over his chest in an advanced stage of his sulk. John climbed in beside him and closed the door. The cab looked like any other London black cab, but John noticed the discreet whirr of the filters and nodded to himself before hitting the com-button allowing him to speak to the woman completely sealed off from them by a glass panel.

"221b Baker Street please, as fast as possible."

"Twenty minutes at the moment according to the planner." The woman replied, carefully not looking back. Not wishing to be seen as any kind of threat by the alpha of an omega in a "delicate" state.

John nodded and sat back beside Sherlock. It was going to be very tight.

Sherlock was still sulking, but he had started wriggling about in his seat too.

"I was looking forward to chasing him!" He moaned eventually. "He was really quite clever."

"I know Sherlock, that is what caused this problem in the first place." John tried to be sympathetic with the unfortunately afflicted detective. "Maybe the police will only have done the legwork by the time this has passed and you will still get to be involved in the final chase."

The detective shot him a disgusted look.

"Don't mollycoddle me John, I don't need it."

John smiled and opened his arms. The consulting detective tried to be nonchalant about clambering into his lap, but was hindered by the length of his limbs and his coat. John thought he was adorable. He wrapped his arms around the thin waist and took a deep inhale at the long, pale neck.

"You smell delicious," John whispered, his voice much lower than normal "and I know just what you need."

Sherlock gave a mewling sigh of "John!" and wiggled his boney arse about, trying to find a satisfactory way of rubbing against the bulge forming in John's trousers.

"We are going to have to have that coat chemically cleaned again, aren't we?" John asked quietly.

"The whole outfit." Replied Sherlock, sounding unapologetic but also deeply put out.

John slid a hand up the inside of Sherlock's thigh, feeling the damp that was starting to penetrate the fibers of his trousers and causing a strong tremor to shake the man in his lap.

"It's ok, we are nearly home and I will take good care of you." John used his reassuring doctor's voice and brought his fingers up to his nose to give them a sniff. "I will fuck you till you're raw."

Sherlock shuddered again. "Damn it John!", he moaned.

John smirked before asking seriously;

"This is happening more often isn't it?"

"Yes, three times in seven months. But I am not having regular cycles." Sherlock replied. "It only used to happen with the _really_ clever ones." There was clearly a pout in there somewhere.

"You weren't living with an unattached alpha before." John replied, nibbling his ear gently. "Your hormones need time to settle into a rhythm after all the shit you put your body through. Or we can put you on suppressors..."

"I can't think on suppressors! Don't make me repeat myself, I hate it."

"Then you will just have to wait for it to sort itself out." John replied stroking a hand over Sherlock's sensitive nipples. "Try and enjoy it." He suggested as the other man shuddered again and hissed;

"Damned transport!"

The cab arrived at Baker Street and Sherlock waited in the car until John had opened the front door, he was clearly distressed at having that much distance between them but John could not risk him being on the street. Every alpha, beta and omega within a block radius would be able to smell him by now. John beckoned to Sherlock, who bounded out of the car and up the front steps. John closed the front door and slid all the locks home before following up the stairs to their flat.

Sherlock had already shed half of his clothes, and pounced on John as soon as he was through the door, kissing him hard and attempting to remove his jumper at the same time. The illogical behaviour showing John just how far gone his flatmate already was.

"Sherlock, take your pills." Captain John Watson commanded, pushing his flatmate off him long enough to toe off his shoes, pull off a sock and hang it on their flat's doorknob as a warning for their landlady, before closing the door and throwing all the bolts.

"I don't want to take them John." Sherlock whined, "They make me feel queasy."

"You don't want to be pregnant either, so take the pills." John replied, quickly going through the flat and closing all the curtains. Sherlock, a half-dressed, clingy shadow at his side.

"I wouldn't mind if it was yours John."

"Ooookay ... That's the hormones talking." John went into the kitchen and retrieved the contraceptives from the medicine box, popped two out and handed them to Sherlock before pouring a glass of water.

"It isn't", sulked the detective.

"Fine, we'll talk about it when you are not stuffed to the gills with nesting hormones and see what you think of the idea of being bred then, but Sherlock if you do not take those pills now, then I swear to God I will not knot you." John calmly unbuttoned his shirt. "I will fuck you into the mattress, then when I feel the knot forming, I will pull out and shoot my load over your stomach."

Sherlock whined "John..."

"The pills Sherlock." John cut him off. "I am serious."

Sherlock swallowed the pills dry and chugged the water down after.

"Good" John praised, undoing his trousers and palming his erection through his pants as Sherlock watched hungrily. "Now get into your room and get naked." John pushed him gently in the direction of his room and smacked his arse for good measure. "I've had your scent in my nose for the last half hour and it is time I did something about it, you cocktease."

Sherlock was naked before he reached his room, and John was a step behind him, stopping only to snag a couple of bottles of energy drink from the fridge. There was no telling how long this would last after all.

Sherlock stood by his bed and waited.

"Well?" John asked "There is no point being coy about it now Sherlock. I know you are gagging for it and I am going to give you it, so get on the bed and spread those ridiculously long legs of yours."

"You are such a romantic John." Sherlock said, laying himself in the middle of the bed with his head on the pillows and bending his knees, so that he was open and on display.

"You don't want romance Sherlock." John said kneeling between the open thighs and giving his own erection a couple of quick tugs. "You are an omega in heat, you want cock. Any cock will do as long as it is capable of putting a nice, big knot in that wet hole of yours." John rubbed the tip of his cock around Sherlock's genitals, rubbing it against Sherlock's own straining mini-penis before sliding it along the wetness between his cheeks.

"I only want your cock John. I want your knot inside me."

John drew away again, to a frustrated protest from Sherlock, and inserted a finger into his dripping anus instead, to check that his partner was loose and lubricated enough. He had no reason to worry, Sherlock was an alpha's porno dream of what an omega in heat should be. Sherlock moaned and clenched around the finger as he released another gush of lubrication and John pulled his finger out before replacing it with the tip of his cock and pushing slowly forwards. Sherlock panted and mewled under him, bending himself practically in half to allow John to push deep.

"You are so tight." John moaned, stroking Sherlock's sweating silken sides and pressing his thighs against his chest. "How many heats have you actually spent with an alpha?"

"Six" Sherlock replied quietly.

"So I am your second? Third?" John asked, distinctly unimpressed by the idea that anyone had penetrated Sherlock before him.

"Third" was the quiet reply. Sherlock was aware it was a bad idea to discuss other alphas when you had one attempting to impale you on his larger than average (even for an alpha) dick.

"I'm the only one to have you for more than one heat?" John asked, still moving slowly, in and out in small movements.

"Yes" Sherlock replied, pleased John had found a positive point.

"Good" John said with a long, hard push into his lover. Sherlock made a pleased noise in his throat and John grasped his mini-penis to stroke it in time with his thrusts. "Can I mark you Sherlock? Please let me mark you." John whispered "You will look so gorgeous with my marks all over your skin."

That was new, there had been no marking in their previous encounters. Sherlock noted in a part of his brain that was somehow still functioning that he was not the only one with "hormone issues".

"Yes, yes" Sherlock nodded enthusiastically and arched trying to get John to go faster. John leaned down and kissed him sloppily instead.

"I am going to start milking you now omega. You will come when I command. Every time you come, you will clench on my dick a bit tighter until my knot forms. Then you will ride my knot like the cockslut you are until I fill you so full of sperm, it will leak out of your ears. Do you understand? Say 'Yes Sir'." Captain Watson breathed in his face whilst giving his ass a couple of long, deep thrusts.

"Yes Sir!" Sherlock could barely get his head around how hot that was.

"I own your ass right now Holmes." The captain told him, fixing him with a look that made him spread his legs wider and strain for more of John's cock.

"John you're so hot. I want your knot so badly" Sherlock panted.

"Sssh, sssh" John soothed him. "Don't worry, I'll knot you. I'll take care of you, I know what you want. I know what you need, I've got a thick knot to fuck you good and hard with, but you have to work for it. Come Sherlock, work for that knot."

Sherlock saw stars and felt his muscles tighten around John.

"Oh yes Gorgeous. Oh God yes! Damn you feel good!"

"John" Sherlock mumbled, feeling raw from his orgasm but already aware another was coming.

"Yes Sherlock what do you need? Let me be good to you."

"I need to be on my knees when you knot me. I need to be your bitch today, Captain."

John had him flipped faster than he could say "woof".

The Beginning

The first time it had happened, John had been taken completely by surprise. Of course he knew Sherlock was an omega, but as he hadn't had a heat in the six months they had been living together, John had assumed his flatmate was taking suppressors. Apparently not. Apparently, it was just another of the wierd things about Sherlock that the man had not seen fit to mention.

John panicked and did the first thing that came to mind in a room full of people where he did not want to cause a stir.

_I can smell you, you are going into heat - JW_

He sent the text and heard Sherlock's phone beep in response.

Sherlock reached into his pocket without halting his examination of the scene. He read the text, startled visibly and wrinkled his nose in disgust.

"Text Mycroft." He growled, not looking at John as he got back to his deductions.

John wasted no time.

_S. is going into heat at a crime scene. Pls advise - JW_

Seconds later his mobile rang and he was unsurprised to see Mycroft's name.

"Mycroft..."

"Don't talk Doctor, we don't have time. I have your location and am sending a car for Sherlock. Tell him to give Lestrade whatever information he has, and get him outside in three minutes."

Mycroft hung up.

John did not have the brain power to worry about Mycroft's abrupter than usual manner. He could only deal with one Holmes at the moment and he knew which one it had to be. The delicious smelling one darting about in front of him.

"Sherlock," he said using his best Captain Watson voice. "Let Lestrade know what you've got. Keep it short, Mycroft will be here in three minutes."

Sherlock glared at him, but couldn't hold it. John was an alpha afterall. Lestrade was a beta, so hadn't noticed anything yet and gave the pair a confused look. Sherlock gave a very put upon sigh and launched into a lightning speed explanation.

John did not even pretend to be paying attention. He was looking at his watch. When two minutes passed, he raised his head and ordered;

"Let's go Sherlock."

Sherlock tried to glare again, failed, and then flounced from the room in disgust.

They met Donovan on the stairs. She screwed up her face.

"Uuuwe! Again Freak?! I told you he got off on this Doctor. Get him out of here. It's disgusting."

John showed the other alpha all his teeth.

"Thank you Sally, that is what I am attempting to do."

Sherlock pushed past her and John hurried after him.

Outside, Dimmock gave a deep sniff and, pulling himself up to his full height (he only had a couple of inches on John), headed over.

"Not now Dimmock." John said drawing himself up as well and planting himself in front of Sherlock.

Dimmock ignored him.

"Sherlock..." he began.

John didn't give him time to say anything else. He clocked him, hard. The other alpha went down and John pushed Sherlock to the gate where he could see two familiar black cars waiting.

Mycroft was already holding the door of one open.

"Get in Sherlock."

Sherlock scowled, but did as he was told. Afterall, Mycroft was an alpha too. Mycroft slammed the door after him, John heard it lock and looked questioningly at the older Holmes.

"With me, Doctor." He said coolly, heading for the second car as the first drove off with Sherlock.

"Shouldn't someone be with him?" John asked. He wanted to say rather more, in a rather less polite tone, but there were things you just don't say to relatives of an omega who has gone into spontaneous heat. John had studied enough Psychology as part of his medical training that even with Sherlock's scent in his nose, he still knew that calling the British government a cockblocker was _not_ in his best interests.

"I rather think that is for him to decide don't you Doctor?" Mycroft replied pulling his phone from his pocket. It was vibrating angrily.

John thought about it and decided that yes, actually Mycroft had done the right thing separating them. He didn't know if he would have trusted any decision either he or Sherlock made at this point.

"Do you want to sleep with my brother Doctor?" Mycroft asked staring at the phone in his hand with a frown.

"That is a really stupid question Mycroft." John replied in total disbelief.

"No, Doctor. I am not asking if you wish to be intimate with an omega in heat. Do you John Watson want to sleep with my brother Sherlock Holmes? Were you interested in the idea before the opportunity _presented_ itself rather suddenly to you?"

"Well yes, but I didn't ever consider it likely."

Mycroft gave a grunt, which John was not capable of interpreting at that moment, and put his phone to his ear.

"Brother!" He said loudly, smiling a fake smile.

"Mycroft you are not kidnapping John now! Give him back! I need him." Sherlock was loud enough that John could clearly hear him without the phone being on loudspeaker and Mycroft winced and held it away from his ear.

"Calm yourself Sherlock, we are right behind you."

"But are you going to the same place I am?" Sherlock whined.

"You are going back to Baker Street Brother. The flat is fully supplied for such a situation. You will be quite comfortable there."

"Damn it Mycroft! What are you planning to do with John?"

"What would you like me to do with the good doctor?"

"Drop him at the flat and _piss off_!" Sherlock roared.

"Are you sure you don't want me to look for _someone else_ of your acquaintance?"

There was silence at the other end of the line. John held his breath. Did Sherlock have an arrangement with an alpha that he was not aware of?

"Don't be dense Mycroft. Who else would you bring?"

Mycroft smiled, and John was surprised to see it looked almost genuine.

"Just as you say Brother."

Mycroft ended the call and gave John an incredibly creepy smile.

"Well John, it would seem that my brother has decided that someone should indeed be with him." The cars drew up in front of their flat. "My assistant has seen to the provisioning of the flat and Mrs Hudson has been taken to her sister's for a few days." He opened a briefcase and pulled out a brown paper bag. "I am sure you know how to administer all of these John. Standard oral contraceptives, which he hates and after-heat pills, which he not only loathes but make him violently sick too. My brother has no history of dryness but there is lubricant, just in case. He will be more emotionally dependant on you than usual and quite frankly alarmingly submissive. If you hurt him Doctor, there will be nothing left of you to find." John's ears were burning as Mycroft handed him the bag. "Now I suggest you go and unlock the front door before I release my brother."

Without a word, John got out of the car, clutching the bag and did as he was told. Sherlock streaked past him.

They didn't talk. John handed Sherlock the contraceptive pills. Sherlock pulled a face but took them. John spent the next 18 hours becoming intimately acquainted with the angles and muscles, sounds, tastes and smells of Sherlock Holmes and was not surprised when Sherlock passed out after that. Spontaneous heats were often short. But intense. John could not even say he was disappointed. Firstly, it had been amazing. Secondly, John was no longer as young as he once was.

They didn't talk afterwards either. Itch rather thoroughly scratched (even if he did say so himself), John did not want to embarrass his friend by talking about the demands of his "transport".

It was Mycroft who talked. He turned up and invited himself to tea while Sherlock was at St Bart's. He gave John a code word that he said Sherlock knew and a business card for a taxi company with a fleet of "discreet" filter cars all driven by female betas, with whom he had set up an account. He threatened John in a friendly manner (rendition, torture, unmarked grave in the desert, his house cursed unto the seventh generation...), drank his tea, ate three Jammy Dodgers and left. John had the impression that the older Holmes was firmly removing himself from his younger brother's sex-life and passing all responsibility to John. Clearly Sherlock was not the only Holmes who (generally) found sex alarming.

John was alert after that for any early warning signs of an impending heat. Months went past with nothing however, although John did regularly try to discreetly test the air, sniffing deeply around his flatmate. He occasionally caught Sherlock rolling his eyes and knew he had not been as discreet as he had hoped. He was too embarrassed to say anything after being caught. Although he justified it to himself that he was just looking out for his flatmate. It wasn't as if he liked Sherlock's smell. No more than any other fertile omega's anyway.

The second time it happened was six months later, when Moriarty came into their lives with a bang, and it lasted for three days. They still hadn't talked about it, but John was well prepared and calm. He said the code word, called the cab and got himself and his suddenly clingy and amorous flatmate to bed ASAP. At times, John found himself wondering vaguely how he was still managing to be hard and where precisely the reserves of ejaculate he was pumping into his flatmate's spectacular arse were coming from. Mostly, however, John did not have enough blood in his head for his brain to work properly because Sherlock had his legs locked round his waist and was begging John to _pleeeeease_ fuck him harder.

Sherlock moved slightly stiffly and sat rather gingerly for a few days after that. John almost raised the subject, but his flatmate was clearly grumpy and he didn't feel like getting _that_ type of tongue-lashing from the other man. Not when it would spoil his smug alpha mood about having visibly given the omega a damned good fucking.

The third time was very short and happened after John pulled rank in Baskerville. John did not know how Sherlock had managed to drive in his condition and John had been terrified that half the base would give chase, so strong were his flatmate's pheromones by the time they left. They only just got back to their room at the inn before Sherlock ripped his soaked trousers off and started rubbing himself desperately against John, significantly impeding John's ability to get his fly down and bend his flatmate over.

The feat was accomplished however, and bent over a bed, still half-dressed, hands balled tightly around fistfuls of quilt, Sherlock gave John a series of explosive salutes and called him "Sir" for the first time, in a voice so wrecked with lust that John was determined no one else would ever get to hear it. His flatmate's neck had never looked so tempting, and John always thought Sherlock's neck was tempting. As he knotted his flatmate deeply into the mattress and listened to the sounds escaping the normally intelligent lips that were nothing but lust and nonsense, John wanted to bite that long, pale neck hard enough to form the mate bond.

John felt a warmth in him that he, boring old John Watson, had managed to do something that Sherlock considered so clever that he was turned on enough by it to go into spontaneous heat. Even if it was just a short one. Then Sherlock was a complete bastard for the rest of their trip. John supposed it didn't help that he was miserably ill from having to take the after heat pills.

So they didn't talk.

The Resolution

This time would be different, John decided. He didn't leave when Sherlock passed out. His flatmate could always throw him out when he woke up if he wanted to. Instead, he wrapped himself around the fucked-out omega and admired the marks on his skin until he fell asleep in their sticky sheets too.

He woke to find Sherlock staring at him, like a curious cat, still unself-consciously naked and unwashed. John stretched and tried to pretend he was not nervous.

"Morning Sherlock." He said.

His flatmate rolled his eyes and John knew that whatever time it was, it was not morning.

"What do you want to talk about John?" Sherlock said testily.

"Us?" John asked tentatively.

"_You_ think you are unattached. Therefore there is no 'Us'." Was the sharp and bitter reply.

That was not what John had expected at all and he sat up fast.

"Sherlock, have I missed something..."

"Inevitably" his flatmate cut him off.

"We've never discussed..."

"What was there to discuss? Everything is perfectly clear. What do you want John?"

"Just you, Sherlock." John replied with soul-deep honesty. "How is everything clear? What do you want?"

"Your babies." Sherlock replied and found himself quickly on his back with John weighing him down.

"Is that a joke Sherlock?" John's voice trembled. Breed Sherlock? Get Sherlock pregnant with gorgeous, frustrating, clever, mad babies? Hell yes, Captain Watson at your command.

"You're here aren't you? You've mounted me through four heats although I only expressly requested you during the first and am quite capable of seeing to my own needs. You decked Dimmock to stake your claim. I told you yesterday I didn't want to take the pills. Mycroft has given his blessing by turning over monitoring and care of my sexual health to you..."

"That was Mycroft giving his blessing?"

"Do you think you would be here if he hadn't? I never found out what he said to Victor, but there was never the chance that I would be spending a second heat with him."

"You can tell me about Victor another time. God I wish you were still in heat so I could bond you now."

"I think you'll find the bite is just a formality now John. Why do you think we got out of Baskerville so easily that time? Our scents have changed."

John growled and nuzzled at his omega's neck.

"I want everyone to know you are off the market."

"Your alpha is showing John." Sherlock smirked.

"Damn right! If my cock didn't feel quite so raw, I'd be mounting you again right now."

"I am feeling a little sensitive myself" Sherlock replied. "Otherwise, I'd be more than happy to spread for you. But you are welcome to kiss me if you'd like... Captain."

"I really need to fuck that sexy mouth of yours." John said

"Yes, yes you do." Sherlock smirked before John kissed him with abandon.

* * *

**Mycroft Worries**

Sherlock's First Heat - Or Why The Holmes' Find Sex Alarming

The household was tense. Mycroft noticed it as soon as he got out of the car and observed the line up. Of course, they weren't going to tell him what the problem was (what his little brother had blown up now) in case he didn't want to be bothered by it. He was going to have to ask. Mycroft wanted to let out a long-suffering sigh, but instead he put a fake smile on his face and asked the butler;

"Is everything satisfactory in the house Prince?"

The butler clearly did not want to answer, he was deeply uncomfortable. However it was his job.

"There is a situation with Master Sherlock, Sir"

Of course there was, when wasn't there?

"Yes?" Mycroft enquired politely.

"He is indisposed Sir"

So, he had blown himself up had he? He hadn't done that in quite some time.

"Has a doctor been summoned?"

"A doctor is not required Sir. You will see as soon as you enter the house, Sir." Mycroft raised an eyebrow but stepped into the house.

Prince was right. As soon as he stepped inside, he smelt the unmistakable smell of omega in heat. Specifically, Sherlock in heat.

Damn, why hadn't he prepared for this? He berated himself mentally. It was being away at university so much, he lost track of how his brother was growing. Developing. Maturing... That was no excuse.

Mycroft took the stairs at a leisurely pace and walked along the corridor to Sherlock's room, the scent getting stronger with every step.

There were... noises coming from the other side of the door. Noises he didn't want to think too closely about.

"Sherlock?" He asked with a firm knock on the door. He didn't get an answer, but he hadn't expected one.

He opened the door and walked briskly through the room to the en suite. He carefully did not look at the sweating mess on the bed that was his brother, attempting to fist himself, as he tried to relieve the cravings he was experiencing for the first time. Mycroft poured a glass of water and returned to the bedroom. Sherlock, now under the covers, looked at him with wide eyes. Eyes that were decidedly more deranged than usual. Mycroft handed him the glass and reached into his jacket pocket. He withdrew a case, from the case he took two pills and handed them to Sherlock. Mycroft had been mounting omegas since he was 16, as was expected of an alpha in his position. He was _always_ responsible about it.

"Take the pills Sherlock." He said calmly, removing his jacket and hanging it over the back of a chair. He felt his brother's eyes on him as he flicked open his cufflinks and began opening his shirt. Mycroft heard a loud swallow, followed by several gulps and the sound of an empty glass being placed on the nightstand.

"Good." He said continuing to steadily and carefully shed his clothes with his back to the bed. He was taking his time to allow his alpha pheromones to work on calming his brother.

"On your hands and knees now, please." He said as he unbuckled his belt. "This will be easier for both of us if we can pretend it is someone else." There was a shuffling noise of bedclothes behind him and when he turned, he was confronted by thin, pale legs ending in flat buttocks. Not his thing at all really, but the smell.. The smell from the lubricant that had left a trail on those thighs. Delightful.

Mycroft knelt on the bed and stroked his hands down the pale back in front of him.

"I am whoever you want me to be." He said. "Just close your eyes and let me look after you."

He slipped a hand between the lanky thighs and spread them wider, he fondled the balls that were hanging heavily and tried to ignore the noises that _he was causing his brother to make_. He pushed the head of his penis into the already well-stretched hole in front of him.

"I will look after you." He assured the quivering mass of flesh beneath his hands as his brain tried to shut down with cries of _so tight, so wet, so good!_

Mycroft was not a passionate lover. Wherever possible he avoided sex because it was distracting and with the wrong person, in the wrong circumstances, could lead to all kinds of complications. He was an attentive lover however, and he deduced the needs of the body beneath him from his previous experience. This person needed emotional signals in order to feel secure in what they were doing, in order to fully submit as he desperately wanted to.

Mycroft kissed the pale skin of his lover's back gently whilst keeping a firm grip on the hips he was thrusting against. He skillfully handled the erect mini-penis so that his hand was soon sticky with cum. The tight anus he was fucking contracted around his rising knot and Mycroft gently but firmly pushed on the back of the neck covered in dark curls, so the head dropped. Relaxed. Submissive.

"Good omega, well done." Mycroft praised. "I am going to knot you now. Just stay relaxed. I will look after you."

Mycroft increased the speed and depth of his thrusts and the omega became vocal, gasping and grunting as his ass took a pounding.

"That's right, let me hear you. Don't be ashamed to let me know what you are experiencing."

The omega keened under him and Mycroft felt his knot begin to explode. He pulled his lover down onto his side and spooned tightly against him, holding him close and filling him with jet after jet of cum.

Mycroft separated himself from his passed out brother some time later and wrinkled his nose at the state of them both. He collected his things, leaving his shirt in the bed so his pheromones could keep his brother relaxed as he recovered, and went to clean up in his own rooms.

Sherlock woke and was glad to find himself alone. He pulled his cigarettes out of his nightstand and lit one. He stripped the bedclothes from the bed and threw them, along with Mycroft's obnoxiously expensive shirt, into the fireplace. He pulled several highly flammable chemicals out of his set and liberally doused the sheets, before throwing the half-smoked cigarette on top, opening all his windows wide and retreating to his bathroom for a very hot shower. He felt utterly disgusted with himself. His body had betrayed him and then he had given in to hormones and let Mycroft fuck him just to stop the cravings. And it had felt good, damn it!

When Sherlock emerged from the shower, he was wearing a bathrobe and the skin that was visible was lobster coloured. He was rubbing his hair dry on a towel when he saw Mycroft sitting in his armchair looking at the ashes in the fireplace. His brother was of course impeccably dressed again and had not a hair out-of-place, his legs casually crossed.

"Sit down Sherlock." He commanded "We will discuss this once, now and then there will be no need for this topic to ever be raised between us again."

Sherlock hated the fact that if he didn't do as his brother said, he would undoubtedly make his own life more complicated. So he sat on the end of his stripped bed and waited.

"Distasteful as it is, it is not that uncommon for alpha relatives to ease their omega kin through their first heats. Particularly if the heat was unexpected. I am sorry I did not prepare for this. I was aware that omegas in our family generally mature at 17. This oversight has now been corrected. The supplies necessary for you to either suppress your heats or experience them more comfortably will be delivered here and to your dorm room this afternoon. There is no reason that this should affect your life at all." Sherlock grunted in a way that communicated that they both knew that was absolute bollocks.

"In the future, you must pay more attention to your body. There are signs of an impending heat that you must take note of so that you can ensure you are where you want to be, with whom you want to be and most importantly _safe_ when it hits you. I take it you did not notice any of these signs this time?"

Sherlock shook his head.

"But you know what to look for? Elevated pulse, flushed skin, lack of concentration..."

"I am not an idiot Mycroft!" Sherlock snapped.

"I never believed you to be, but you struggle against your biology at every turn and I worry about you."

Sherlock grunted. Mycroft got to his feet and brushed the creases from his suit jacket.

"The code word is Ponderous House."

Sherlock gave a disgusted snort.

"I will do whatever I deem necessary if that phrase is ever mentioned between us." Mycroft stated despite his brother's disdain. Whether that included fucking him up the arse again was left undiscussed.

Sherlock immediately started himself on heat suppressors. After sticking with them for a week, it was clear they could not be the solution. He felt like his head was stuffed with cotton wool and his nose barely functioned at all. Deciding that he was not going to be able to stop his heats completely, Sherlock investigated the causes of irregular and infrequent heats and, never having been one for doing things by halves, began to implement a new regime of not eating or sleeping, and increased his nicotine and caffeine intake exponentially.

In his office at Oxford, where he was engaged in writing his PhD on encouraging omega rights in society, Mycroft received reports about his brother's new behaviour. And he worried. Constantly.

Who Is Victor?

"Don't be such a cretin Victor, we both know you've got more than that."

"But what makes you think I want to sell it to you?"

"The fact that I will report where your essays really come from if you don't."

"See, there you go being a total dick again Holmes. No wonder no one can stand you."

"Just give me what you've got and get out." Sherlock said, he could feel his pulse hammering and he needed a hit.

"If I've got anything left once I've done my rounds, I'll swing by again." Victor said counting the money in his hand.

"Whatever, just get out." Sherlock was already preparing his equipment when the door closed behind his dealer, and the only person at Cambridge who took Sherlock's attitude with a shrug.

So his pulse had not been hammering because he needed a hit. Or at least not only a hit. It had been nine months since his last heat, the longest he had managed yet. He wondered what had brought it on this time. He hadn't done anything different or exciting ... Except reading that Criminology book he'd found in the library...

Sherlock was high as a kite as he fucked himself with his dildo. He was so out of it that the first he noticed of Victor's return, was the smell of the alpha's pheromones as he stood right in front of him. He hadn't locked his door.

_Idiot! _One part of his brain shouted. Another part of his brain, the lizard part, was not at all disturbed by the development.

"God you are gorgeous. I knew there was a reason I put up with your shit."

Victor studied him closely. Sherlock knew his hair was mussed and his skin was flushed and sweaty. He must have smelt intoxicating, his dildo was well covered in his own lubrication. Sherlock studied Victor just as intently. Short, blond, muscular, _alpha_ Victor who smelt like sex on legs at that moment.

"Wouldn't you prefer the real thing right now Holmes?" The alpha asked and Sherlock was in no position to deny it.

Sherlock was awoken by his door being smashed down. This was not an occurance that was common, but probably only because he was an omega and had a specially reinforced door to ensure his privacy. If he was clever enough to lock it that is. Which apparently Victor had been.

The same Victor who had just been pulled bodily out of his bed by Mycroft. Bloody Mycroft! Who looked completely calm, except for the fact that he had Victor around the throat. He was wearing gloves, Sherlock noted, but still looked like he was touching something utterly revolting. Well, Victor never was fastidious about his grooming and Sherlock supposed that post-mounting he might be a bit riper than normal.

"Hello Mycroft." Sherlock said and realised he was still a bit high. "It seems that I just can't get fucked without you showing up for an awkward conversation afterwards."

"I will deal with you shortly Brother." Mycroft wrinkled his nose not taking his eyes off the struggling Victor. "Go and shower, you reek."

Sherlock cursed the hormones that remained in his system and forced him out of his bed at the alpha's order.

Victor was gone when he returned to his room. Unfortunately Mycroft was not. Once again he sat impeccably dressed, and apparently at ease, with the windows of Sherlock's dorm room wide open. His sheets, and Mycroft's gloves, were gone, he wondered where as there was no convenient fireplace this time and then decided he didn't actually care.

"Take the pills brother." Mycroft said gesturing at the nightstand. "Care to explain what you were thinking?"

"Not much actually." Sherlock replied casually. "See, every so often I turn into a bundle of hormones and am completely unable to make logical decisions." And it leaves me raw and drained. He didn't need to say it, he knew his brother saw it.

"Sherlock, you are going to rehab. This self-destructive spree has gone on long enough."

"I am not self-destructive, I have it under control."

"You have nothing under control. You were so messed up that you did not take even basic safety measures. You did not lock your door. You did not take any contraceptives. You were high and allowed yourself to be mounted. Have you even looked at yourself?"

Sherlock raised his eyes to look at the mirror on his wardrobe door. His neck was a mass of dark marks.

"You could have ended up bonded to that... cheating, drug-dealing, English Literature student."

Sherlock was not sure which part of that row of judgements Mycroft felt was worst, but he reluctantly admitted that his brother had a point.

"Where is Victor?" He asked, partly just to upset Mycroft for being right.

"Gone Sherlock. For quite some time. **You will not be seeing him again**."

And that was the voice of the alpha in his family. A voice Mycroft never used because he had always preferred to win arguments with his brother fairly and not use his biology against him. Sherlock sighed.

"What did you see in him?" Mycroft asked finally, gently.

"He was short and blond and muscular." Sherlock replied leaving the unspoken _and nothing like you _hanging in the air. "And there." He added, because Sherlock was always basically honest.

"Oh Sherlock" said Mycroft who heard nothing but loneliness in his brother's voice. He stood up and went to the door. "Finish your degree Brother, it is time you got out of here. And get the drugs under control or I will force you into rehab."

Sherlock was miserably ill for the next few days as the after-heat pills took effect. He hated all alphas. He hated himself.

In his office in London, where he was employed "in a minor government position" with fingers in many pies, Mycroft received reports about his brother. Even the news of his double first did not alleviate his worry for his sibling. So he worked on getting new anti-discrimination laws passed for the omega equality lobby, and worried. Constantly.

I Don't Wanna Go To Rehab, But My Alpha Said Go, Go, Go

"Sherlock, you are going to cause me to go prematurely grey."

"As if you don't dye your hair anyway Mycroft. That shade of red is just not in the family."

It was several days after "The Incident", out of necessity. Sherlock had been "indisposed" at his flat in Montague Street, where Mycroft had had him delivered, after several beta members of his staff had "intervened" to stop a (not inconsiderable) group of alphas slugging it out to decide who got the "prize". Meaning Sherlock, who really should not have been on the streets at that point and who had put in a desperate (embarrassing) call to Mycroft where he managed to sputter out nothing but the damned (embarrassing) code word.

Mycroft refused to rise to the bait, he was angry about his brother's lack of care but he was more scared about what it might indicate.

"**There will be no argument this time Sherlock**, your bag is packed, the car is waiting. You will find that the staff at the institution you will be residing in are very well informed about you and your various talents. **You will remain there until you are clean and likely to remain that way.**"

And there it was, the alpha voice again. Sherlock left for rehab.

A Trouble (Discreetly) Shared

Mycroft sat in his office at the club and thought. It was a good place for thinking. Quiet. Slow. Somewhat 19th century.

He had decided that his brother needed someone and was collecting his data. Not just someone for "that time of the cycle" (Sherlock didn't have cycles, he had managed to throw his biology off that much), but someone steady who could deal with Sherlock on a day-to-day basis. Someone who was intelligent enough that Sherlock could stand them, but not so intelligent that they would outshine Sherlock's showing off. Someone useful... Someone he had found for himself, or at least appeared to have. Sherlock would never accept anyone he considered a plant, or worse, a blind date organised by his interfering older brother.

Mycroft knew there had been an experiment done once that suggested all humans are only separated by six degrees. Mycroft knew a lot of people and he began to put out feelers.

_Short, muscular, blond, intelligent, good under pressure, __**alpha male **__wanted_...

Mycroft always gets what he wants, sooner or later, by fair means or (and sometimes he even genuinely regrets it has to be this way) foul.

John Watson returned from Afghanistan and was dead inside. Sherlock returned from rehab and was forced to stay with Mycroft "under observation". Mycroft put on his best stiff upper-lip and bore it while he waited for the chain of degrees of separation he had set-up to bare fruit.

Whilst Sherlock had been in rehab, Mycroft had written to a head hunter of his acquaintance with a very good tip about a position she needed to fill.

The head hunter was delighted and wrote to the address that Mycroft had given her with an attractive offer that would however require relocation.

Mrs Hudson wrote to Sherlock to say that she was glad he was feeling better and that of course Mycroft was right and he should not go back to Montague Street. 221b had just become free and she was willing to give him a good rate for it if he wanted it. Sherlock wanted away from Mycroft, but without Mycroft's help (not forthcoming, he needed to be "watched for his own good" apparently) he could not afford it.

Sherlock thought about it. A lot. Mike Stamford found him gazing at the flatshare board in St Bart's one day and could not keep from commenting. Sherlock deduced all the people who had ads up, poured scorn on all of them and bemoaned the fact that there were just no suitable flatmates out there.

Mike Stamford met John Watson in the park.

Shortly afterwards, Mycroft met John Watson for the first time, in a warehouse. That night, Mycroft Holmes was convinced that whilst he was still always going to worry about his little brother, that worry need no longer be constant, now that John Watson was in the picture.

He could not wait for "the happy announcement" to come. It would be only a matter of time.

* * *

**Epilogue**

Delays

His brother was in Argentina, and to say he was furious really was to miss the opportunity to use incandescent. That was not his problem right now however, because before him stood John Watson, and Mycroft was not sure a word had been invented yet for how very, very angry the other alpha was at this moment.

"Is it blood money Mycroft? Does it sooth your conscious? You sold your brother out and now you are trying to pay me off?"

"It is Sherlock's trust fund, it comes to you as his surviving partner."

The only bright spot Mycroft could see in the whole mess (aside from the death of James Moriarty and the now imminent destruction of his network) was that thankfully his brother and the doctor had not fully bonded. He did not know if either man would have survived the separation if they had. Not to mention complications to any pregnancy. As it was, he was quite sure there was going to be substantial work required to the relationship when his brother was able to return. John was a mess, Mycroft was pained to see his almost brother-in-law clearly was not taking care of himself.

"I don't want your money Mycroft. I want Sherlock back, can you do that?"

"No John" Mycroft sighed "You know I can't."

"Then keep the hell away from me!" John roared. "And if I see any of your people, or your suspicious black cars following me about, I'll flatten them. Even if you send Anthea."

"Understood John. The money is yours, use it or don't, but my brother would have wanted you to have it. I hope you will eventually manage to forgive me. Believe me, I know how badly I have messed up."

"I seriously doubt it." John replied and strode out.

Mycroft knocked back a large scotch and settled down to think. His brother needed someone to come back to, which meant Dr Watson could not be allowed to self-destruct. That was unfortunately looking horribly possible. Mycroft followed Dr Watson (he could not allow himself to think of him as John at the moment) with his cameras until he got on the underground. Then Mycroft had his train delayed in a tunnel while new cameras were placed in 221b.

Mycroft authorized the purchase of a used, green Nissan Micra (green things are often less likely to be actively seen according to research Mycroft had read, an evolutionary developement caused by our environment and the abundance of trees and grass, et cetera) and assigned a team of specially trained beta women to watch Dr Watson. Mycroft was aware of how underestimated betas were and made use of the fact regularly. If you wanted a James Bond, you sent an alpha, an omega could provide excellent distractions, but for serious spying you could not beat betas.

John Watson would be at Baker Street to welcome Sherlock home, whether he wanted to be or not. No other outcome was acceptable.

* * *

**AN : The phrase "Ponderous House" is from the poem "Metaphors" by Sylvia Plath.  
**

**There is no post-Reichenbach or post-Return sequel to this, though I am sure that John forgives Sherlock and they have lots of genius offspring that Uncle Mycroft can spoil rotten, once he has been forgiven too. That's all folks.  
**

******Decent formating, we can't haz it :-/ Sorry, maybe next time. **


End file.
